Denture articulator



Nov. 13, 1945. w. c. WHITTEMORE 2,389,101

DENTURE ARTICULATOR Filed April 7, 1945 3 Sheets-Sheet 1 INVENTOR g WINTHROP C. WH/T EMORE A ORNEY Nov. 13, 1945. w. c. WHITTEMORE DENTURE ARTICULATOR Filed April 7, 1945 5 Sheets-Sheet 2 I r 1 v ENTOR W/NTHRUP 'C. WH/TTEMURE Nov. 13, 1945.

w. c. WHITTEMORE 2,389,101

DENTURE ARTICULATOR Filed April '7, 1945 I5 Sheets-Sheet 3 INVLNTOR I INTHROP C. WH/ EMORE.

/ BY I AT CRNEY are partially or fully adjustable.

Patented Nov. 13, 1945 DENTURE ARTICULATOR Winthrop 0. Whittemore, Port Washington, N. Y., assignor to The Dentists Supply Company of New York, New York, N. Y., a corporation of New York Application April '7, 1945, Serial No. 587,186

9 Claims.

The invention relates to dental articulators emp yed in denture prosthesis for arranging the teeth in harmon with average mandibular movements or with the mandibular movements of the individual.

Articulators are designed to reproduce as nearly as possible the movements of the human mandible. Some of these instruments are permanently adjusted to average movements. Others As the movements of the mandible are quite complex, designers of dental articulators have been compelled to devise elaborate mechanisms in order that these complex movements may be reproduced as faithfully as possible. Articulators of the type which are permanentl adjusted to average movements have a fixed incisal table, whereas the partially orfully adjustable type generally has an adjustable incisal table. However, the incisal table adjusting mechanisms heretofore known or used have been subject to a number of disadvantages. They have been quite complicated in construction, requiring a high degree of knowledge and skill for correct operation, as well as being expensive to manufacture. This is true, for example, of one of the best designs of articulator now on the market, which has an incisal table with a pivotal mounting which carries a degree quadrant, and which has locking means for holding the table in various positions of angular adjustment. It is an object of my invention to provide an articulator having a simplified incisal table adjustment which is both less expensive to manufacture an which can readil be manipulated by the least experienced laboratory technician to give a variety of predetermined angular adjustments of high precision, and which is adapted for incorporation in the design of articulators of all of the types mentioned above.

Other objects and advantages Of my invention will appear as the description proceeds. In the drawings:

Fig. 1 is a side elevational view of a preferred form of my improved articulator.

Figs. 11 and 12 are enlarged diagrammatic views of the modified construction, illustrating the manner in which the engaging element of the table and lower bow cooperate to maintain the same elevation of the center of the table for all angular adjustments of the table,

In its general arrangement, the articulator comprises a lower model bow I, frame 2, upper modelbow 3, and an incisor guide pin l which cooperates with an incisal table member 5-carried by the lower bow.

The upper and lower bows have apertures 6 in which the plaster models of upper and lower dentures are mounted. (Other well known means for mounting the models ma be employed.) The frame 2 is fixed to the lower bow, as by the screws 1,

The upper bow is pivotally mounted on the frame in such a manner as to reproduce or simulate the movements of the human mandible when the upper bow is moved with the incisor guide pin in contact with the incisal table. To thi end the upper bow is provided with a pair of pivot pinsor screws 8 engaging arcuate depressions 9 in the top of the frame 2 to provide movable rotation centers between the upper bow and frame.

Relative movement between the upper and lower bows is controlled further by an approximate functional reproduction of the human condyles and glenoid fossae. For this purpose the upper bow is provided with a pair of forwardly and downwardly extending cars In having arouate lower surfaces ll simulating glenoid fossae and arranged for slidable engagement with the upper ends of the respective pins l2 simulating the condyles. Relative movement between the upper and lower bows and the jaw or jaws carried thereby is controlled in part by the condyle path predetermined by the disposition of the glenoid fossae H and the condyle pins.

A spring i3 secured to the frame 2 as by a screw M may be provided to urge the bows together. This spring may further be arranged for cooperation with a surface [5 on the upper bow to hold it in a raised position during mounting of the models or in making adjustments in the dentures.

The pivotal construction which I have described forms no part of the present invention except as utilized in conjunction with my novel incisal table construction, and it will be understood by those skilled in the art that other wellknown constructions may be employed for simulating the action of the human condyle and dyle inclination, whether the latter is fixedor ad"- justable. With a fixed, or average, condyl inclination, a chart can be furnished showing the incisal table surface I6 remains uppermost, and then reinserting the block into the bow, we obtain a predetermined incisal table angle of 8 as shown in Fig. 5. Again, by lifting the block from th'e slots when in the position shown in Fig. and inverting it by turning about a horizontal axis to bring the surface I! uppermost and replacing the block in the bow, we obtain (assuming an angle of 23 between surfaces l6 and II) a predetermined incisal table angle of 31 as shown in Fig. 6. This angle is determined by the rela- Itive disposition of the lugs and slots and the angle between the surfaces [6 and I 1. Thu it will be seen that with only two incisal table surcorrect table angle for each cusp inclination.

- to three predetermined positions, for example,

0, plus 8, and plus 31. Other combinations of angles can be used. The incisal table member 5 comprises a block which'preferably is made of metal and has incisal table surfaces l6 and I! on opposite sides thereof arranged at an acute angle to one another. Lateral flanges I8 extending vertically at the edges of the incisal table surfaces serve to limit the extent of the lateral movement of the incisor guide pin. Cooperating engaging elements are provided on the incisal table" block and lower bow, respectively, arranged for mounting th'e block on the lower bow in a plurality of predetermined fixed positions selectively to place the opposed incisal table surfaces l6 and I! at various angles to the horizontal.

In the preferred embodiment I illustrated, these cooperating engaging elements take the form of laterally projecting lugs lS at the ends of the block and a complementary pair of slots in the lower bow arranged to receive the lugs in'normal, reversed and inverted positions-i. e., in at least three predetermined fixed positions so as to bring the opposed incisal table surfaces I6, I! to at least three predetermined fixed angles to the horizontal. I

' As illustrated, the laterally projecting lugs l9 are generally rectangular in form so as to provide parallel flat surfaces engaging the complementary flat surfaces on the upstanding ears'2l defining the sides'of the slot 20. The angular disposition of the complementary'engaging surfaces of the block and lower bow, in conjunction with the angular disposition of the incisal table surfaces, determines the incisal table angle. For example, in' the specific embodiment I have illustrated, the

- lugs 19 are set at an angle of 86 to the incisal table surface l6 of the'block 'and the slots 20 are set at an angle of 86 to the plane of the lower how, i. e., to the horizontal, so that when the block is assembled with the bow in the manner shown in Fig. 4, there is provided an incisal table which is parallel to the lower bow, or the angle of which may be said to be 0. By removing the block 5 and reversing it anteriorly-posteriorly by rotating 180 about its vertical axis so that the faces there are provided a total of at least three predetermined fixed incisal table angles.

The angles preferably are marked on the incisal table surfaces in such a manner that as the operator faces the articulator and looks down at the table, the angular marking which he reads surfacelfi will have two markings 0 degrees" 'and'.8 degrees, each written near one edge of the surface, and having the base of the letters toward the edge. Thus, as the operator looks at the'table, one of the degree markings will be inverted and the other will be right side up, and the one which is right side up will always give the true reading for the table angle. This will eliminate any possibility of confusion or errors in setting. I

It will be observed that the lower how I is recessed as at 22 so that the block is positioned between the vertical walls 23 forming the sides of this recess.

The modified construction shown in Figs. '7 to 12, inclusive, provides an additionalrange of adjustment of the incisal table angle, the angular disposition of the lugs and slots and the angle between the two incisal table surfaces 24 and 25 of the block 5 being selected to provide predetermined incisal table angles of 0", plus 10,

plus 20, and plus 30. In the exemplified form 1 of this embodiment, the lugs 26 are arranged atan angle of to the incisal table surface 25, the slots 2'! are arranged at an angle of 75 to the plane of the lower bow, i. e., to the horizontal, and the angle between the surfaces 24 and 25 is 10; so that when the block is assembled with the bow in the manner shown in Fig. 7, there is' provided an incisal table'which is parallel to the bow, or the angle of which may be said to be 0. By lifting'the block 5 from the slots when in the position shown in Fig. 7 and inverting it by turning about a horizontal axis to bring the surface ZS'uppermost and replacing the block in the how, we obtain a predetermined incisal table angle of 10 as shown in Fig. 8. Again, by

60 'lifting the block from the slots when in the position shown in Fig. 8 and reversing it anteriorlyposteriorly by rotating about its vertical axis so that the incisal table surface 25 remains up- Dermost and then reinserting the block into the bow, we-obtain a predetermined incisal table angle of 20 as shown in Fig. 9. Finally, by lifting the block from the slots when in the position shown inFig. 9'and inverting'it by turning about a horizontalaxis to again bring the surface 24 uppermost and replacing the block in the bow, we ob- ..tain a predetermined incisal table angle of 30 and slots'and the angle between the surfaces 24 and 25. In this embodiment, with only two incisal table surfaces, there are provided a total of four predetermined fixed incisal table angles.

With particular reference to Figs. 11 and 12, I will now describe an important feature of my preferred construction in which the engaging elements of the table and lower bow cooperate in such a manner as to maintain a uniform elevation of that point of the table engaged by the incisor guide pin when the latter is at its center position or position of rest, for all angular adjustments of the table. This is important in order that the upper and lower bows may be maintained in parallelism, again speaking with reference to the center position of the guide pin on the table.

In my preferred articulator design this is accomplished by so constructing the lugs on the block and the slots in the lower how I that the lugs will extend farther into the slots when the table is adjusted to one angle than they will when, the table is adjusted to another angle as by reversing the table anteriorly-posteriorly. Thus, when the block is adjusted to give an incisal table angle of 0 as shown in Fig. 11, the lugs are maintained in a higher position in the slots than when the block is reversed to obtain a table angle of 30 as shown in Fig. 12. For this purpose the bottom of the lugs as viewed in Fig. 11 are stepped, as at 29, so that the forward parts 30 of the bottom surfaces are lower than the rearward parts 29. The terms forward and rearward are here used only with reference to what we may term the normal position of the incisal table member shown in Fig. 11. The bottom of the slot 21 also is stepped as at 3| so that it is higher toward its forward portion 32 than at the rearward portion. A comparison of Figs. 11 and 12 will show that the lugs 26 extend farther into the slots when the incisal table is in the position shown in Fig. 12 than they do when the table is in the position which wehave termed the normal position. The height of the steps 29 and 3| is proportioned in such a way as to maintain a given central point 33 of the surface of the table at the same height for both the normal position of Fig. 11 and the reversed position of Fig. 12. This may be observed by noting that the height of the point 33 above the top of the lower bow is the same in both views, as shown at a.

Figs. 11 and 12 show the extreme positions of the particular incisal table arrangement here selected for the purpose of illustration. These extreme positions are the ones which would cause the greatest difference in the elevation of the given central point 33 of the surface of the table in the absence of the provision of the particular structure which I have just described. The two intermediate positions of and illustrated in Figs. 8 and 9 are close enough that the height of this given central point is substantially the same for the two positions. Hence it may not be necessary to provide a step in the top surface 34 of the lugs (34 is the lower surface as viewed in Figs. 8 and 9). However, wherever a disparity between the height of the given central point 33 becomes apparent between two reversed positions of the block, means similar to that shown for the 0 and positions may be provided in order to insure that the incisor guide pin 4 will remain at the same elevation for the two positions, keeping the upper and lower bows in parallelism.

It may be observed here that Figs. 7 and 10 (corresponding to Figs. 11 and 12) represent reversed positions of the block with incisal table between the incisal guide pin 4 and the sleeve 35 through which it extends. Normally, the pin is positioned with its upper end flush with the top of the upper bow 3 at 36, but this adjustment may be varied where desired by loosening the set screw 31 and sliding the pin a little one way or the other, looking it in its adjusted position by means of the set screw.

The projecting lugs H] or 26 of the incisal table member may extend flush with the outer surface of the vertical walls 23 of the lower bow, although I prefer that they extend beyond these walls as shown in Fig. 3, for the lugs should have a snu fit with the slots, and in removing the incisal table member from the how, it may be found advantageous to tap the under sides of the lug extensions with a mallet to assist in removal.

If desired, the articulator may be provided with means for attaching a face bow in pivotal relationship to the frame, such as the trunnions 28. It will be understood by those familiar with this art that other well-known features of articulators may be embodied as may be desired. The terms and expressions which I have employed are used in a descriptive and not a, limiting sense, and I have no intention of excluding such equivalents of the invention described, or of portions thereof, as fall within the purview of the claims.

I claim:

1. In an articulator, an incisal table member comprising a block having incisal table surfaces on opposite sides thereof arranged at an acute angle to one another, a. lower bow, and cooperating engaging elements on the block and lower bow respectively, arranged for mounting the block on the lower bow in a plurality of predetermined fixed positions selectively to place the 0pposed incisal table surfaces at various angles to the horizontal.

2. In an articulator, an incisal table member comprising a block having incisal table surfaces on opposite sides thereof arranged at an acute angle to one another, a lower bow, projecting lugs at the ends of the block, and slots in the lower bow arranged to receive the lugs in normal, reversed and inverted positions selectively to place the opposed incisal table surfaces at various angles to the horizontal.

3. In an articulator, an incisal table member comprising a, block having incisal table surfaces on opposite sides thereof arranged at an acute angle to one another, a lower bow, a pair of laterally projecting lugs at the ends of the block, and a complementary pair of slots in the lower bow arranged to receive the lugs in a plurality of predetermined fixed positions.

4. In an articulator, an incisal table member comprising a block having incisal table surfaces on opposite sides thereof arranged at an acute angle to one another, a lower how, a pair of laterally projecting lugs at the ends of the block, and a complementary pair of slots in the lower bow arranged to receive the lugs in at least three predetermined fixed positions.

5. In an articulator, an incisal table member comprising a block having incisal table surfaces on opposite sides thereof arranged at an acute angle to one another, a lower bow,v and cooperating engaging elements on the block and lower bow respectively, arranged for mounting the block on the lower bow intnormal, reversed and inverted positions selectively to bring the opposed incisal table surfaces to at least three predetermined fixed angles to the horizontal.

6. In an articulator, an incisal table member and a lower bow, cooperating engaging elements on the incisal table member and lower bow respectively, arranged for mounting the incisal table member on the lower bow in a predetermined fixed position and also in a second predetermined fixed position in which the incisal table member is reversed anteriorly-posteriorly from the first-named fixed position.

7. In an articulator, an incisal table member and a lower bow, cooperating engaging elements on the incisal table member and lower bow respectively, arranged for mounting the incisal table member on the lower bow in a predetermined fixed position and also in a second predetermined fixed position in which the incisal table member is reversed anteriorly-posteriorly from the firstnamed fixed position, the cooperating engaging elements on the incisal table member and lower bow being constructed and arranged to maintain a given central point of the surface of the table at the same height for both of said positions.

8. In an articulator, an incisal table member and a lower bow, projecting lugs at the ends of the table member, and slots in the lower bow arranged to receive the lugs when the table member is in one position and when it is in an anteriorly-posteriorly reversed position selectively to place the surface of the incisal table member at different angles to the horizontal.

9. In an articulator, an incisal table member and a lower bow, projecting lugs at the ends of the table member, and slots in the lower bow arranged to receive the lugs when the table member is in one position and when it is in an anteriorly-posteriorly reversed position selectively to place the surface of the incisal table member at difierent angles to the horizontal, the bottom of the lugs and the bottom of the slots'being stepped sothat the lugs extend farther into the slots in the one position than in the other whereby a given central point of the surface ofthe table is at the same height for the different angles of adjustment.

WINTI-IROP C. WHITTEMORE; 

